Articular repair following injury or degeneration represents an acknowledged major and growing clinical problem, and joint replacement is generally regarded as appropriate only for the older patient with advanced cartilage loss. For the younger patient, the treatment modalities have significant limitations. There are a growing number of new technologies and methodologies attempting to address articular cartilage repair, however there is no uniform method of assessing their safety and effectiveness or efficacy. The objective of this SBIR project is to establish ASTM Standard Methods (a large animal model and outcome measures) for assessing the safety and effectiveness or effectiveness of products for articular cartilage repair. There are multiple animal models for articular cartilage repair and regeneration, ranging from rodents to very large animals including horses. There are a large number of different analyses that can be performed used as outcome measures. This leads to an inability to uniformly assess potential clinical performance, compare performance between potential therapies, or develop a consistent understanding of underlying mechanisms of repair. There is therefore a substantial need to develop an in vivo of assessing cartilage repair that can be used to support clinical studies, is consistent between users, and is clinically relevant. Our interdisciplinary team has substantial experience in using large animal models for cartilage repair, and recently we and others have successfully used the goat as a method of assessing cartilage repair. Team members have also established a number of key outcome measures that are valuable in providing a quantitative assessment of cartilage repair. Our team also has substantial experience in developing ASTM standards. We therefore propose to combine the animal model expertise, the analytical expertise, and the standards expertise, to generate a set of standard methods for cartilage repair, which are shown to be reproducible between research centers, and can generate uniform data that is appropriate for submission to the FDA to support initiation of clinical studies. The goals of the Phase I project have been achieved. The Phase II project will (a) characterize the animal model up to 12 months after surgery, (b) validate the model and complete the ASTM standard for the model, (c) develop ASTM standards for quantitative outcome measures in biochemistry, bioengineering, and imaging. Specific Aim 1. Characterize the goat model of osteochondral defect and repair at 3, 6 and 12 months. Specific Aim 2. Demonstrate reproducibility of the animal model and complete the ASTM Standard Method. Specific Aim 3. Validate methods and develop ASTM standards for outcome measures. The result will be a standardized animal model appropriate for assessment of techniques and products for cartilage repair, together with standardized outcome methods. The overall outcome will be a uniform and robust methodology for assessing cartilage repair.